Generally, a liquid crystal display (LCD) apparatus includes a liquid crystal panel including a liquid crystal to display an image and a backlight unit emitting light to the liquid crystal panel to supply the light to the liquid crystal panel.
Hereinafter, the liquid crystal panel, in order to display the image, includes a thin film transistor (TFT) substrate which includes a plurality of pixels having a TFT structure as a base, a color filter (CF) substrate which corresponds the TFT substrate and is configured to display colors of the image, and a liquid crystal interposed between the TFT substrate and the CF substrate. Also, the backlight unit includes a light emitting diode (LED) which generates light using semiconductor characteristics, and a light guide plate, on which the LED is disposed, guiding the light generated from the LED toward the liquid crystal panel.
Here, the LCD apparatus may further include a reflecting plate which reflects a light emitted from a lower portion of the light guide plate toward the liquid crystal panel, thereby efficiently utilizing the light. In this case, the LCD apparatus may also reflect a sunlight incident from outdoor through the reflecting plate toward the liquid crystal panel, thereby increasing luminance.
Also, the LCD apparatus may further include a diffusion sheet interposed between the light guide plate and the liquid crystal panel to diffuse light exiting from an upper portion of the light guide plate, and a prism sheet condensing light diffused from the diffusion sheet.
However, since a conventional prism sheet is composed of one film having one prism pattern formed in one direction, the conventional prism sheet cannot condense light exiting from the diffusion sheet in a direction perpendicular to the one direction.